1. Field of the Invention
The present invention relates to an ultrasound operation apparatus that performs operations using ultrasound oscillation and controls cavitation generated in accompaniment with ultrasound oscillation, a cavitation control method, and an ultrasound transducer control method.
2. Description of Related Art
In recent years, ultrasound operation apparatuses that perform operations on living tissues using ultrasound oscillation generated by an ultrasound transducer have been widely used. When ultrasound oscillation is applied to living tissues, cavitation may occur due to liquids contained in living tissue. The cavitation is the generation of vapor bubbles caused by liquid evaporation when the pressure of a liquid falls below a vapor pressure determined by the temperature of the liquid.
Accordingly, when compression waves are generated using ultrasound oscillation, the generation of negative pressure causes cavitation.
In this light, for example, in Japanese Patent Application Laid-Open Publication No. 2002-537955, an apparatus is disclosed in which therapeutic ultrasound is irradiated to a position inside a body while a cavitation level is monitored using a hydrophone.
In addition, International Publication No. WO2005/094701 discloses an apparatus provided with a sound pressure signal receiving probe on an ultrasound irradiating piezoelectric element, which controls ultrasound irradiating conditions using the sound pressure signal receiving probe according to a sound pressure signal emitted from cavitation bubbles.